Starter pinion engaging mechanism



Dec. 16, 1952 R. R. ROBINSON ETAL 3 STARTER PINION ENGAGING MECHANISM Filed Nov. 7, 1951 2 SHEETS--Sl-IEE'I' 1 IN V EN TORS.

1952 R. R. ROBlNSON ETAL 2,621,532

STARTER PINION ENGAGING MECHANISM Filed Nov. 7, 1951 2 srms'rs-suEm'r z INVENTORSQ A TTOR1VE Patented Dec. 16, 1952 STARTER PINIoN ENGAGING MECHANISM Ronald R. Robinson, Morton, and Frederick B.

Laux, Peoria, 111., assignors to Caterpillar Tractor 00., Peoria, 111., a corporation of California Application November 7, 1951, Serial No. 255,281

7 2 Claims.

1 This invention relates to the starting mechanism for an internal combustion engine and more particularly to the starter pinion engaging mechanism therefor.

The invention is particularly adapted for use in' connection with starting mechanisms of the type disclosed in Patent No, 2,481,783 to Robinson et al. for Starting Mechanism for Internal Combustion Engines which issued on September 13, 1949. This patent discloses a starting engine mounted on the side of a primary engine and a driving connection from the starting engine including a pinion gear adapted to mesh with a ring gear on the flywheel f the primary engine. The control mechanism for engaging the pinion gear with the ring gear is disclosed together with centrifugally actuated latching mechanism for holding the pinion gear in engagement with the 'ring gear during starting of the primary engine.

It is to the control mechanism for engaging the pinion with the ring gear with which the present invention is concerned.

The control mechanism disclosed in the above identified patent has been found to have certain disadvantages when used on some engines. For example, part of the pinion engaging mechanism extends beyond the end of the pinion and interferes with the positioning of auxiliary apparatus driven by the engine such as marine gears, electric generators, and the like.

It is, therefore, an object of the present invention to provide a control mechanism for engaging the starting pinion gear with the flywheel ring gear in which none of the control parts extend beyond the end of the starter pinion gear. It is another object of this invention to provide a control mechanism of the type described in which substantially all of the sliding parts are enclosed within an oil tight housing to protect it from the accumulation of foreign material and to insure adequate lubrication of all of the sliding parts. Another object of this invention is to provide a control mechanism of the type described of unusually simple design which may be easily and cheaply manufactured.

Other objects and advantages of this invention will be made apparent in the following description wherein reference is made to the accompanying drawings.

In the drawings:

Fig. 1 is a fragmentary view in section through a portion of a starting engine and the primary engine showing in detail the clutch parts associated with the starting engine flywheel, the driving mechanism between the starting engine and primary engine disclosing the pinion engaging mechanism, and the control means for the pinion embodying the present invention.

Fig, 2 is a sectional View taken along line II-II of Fig. 1; and

Fig. 3 is a fragmentary sectional view taken along line IIIIII of Fig. 2.

In Fig. 1 of the drawings a part of a conventional internal combustion engine is illustrated as comprising a housing In enclosing a fly wheel H having a ring gear H! which may be formed integrally therewith. The primary engine carries a separate starting engine only par-t of which is shown as comprising a fly wheel [3 carried on a crank shaft, part of which is shown at H and a housing It enclosing the fly wheel. Power from the starting engine is transmitted througha drive shaft H to a pinion gear l8 which is adapted to be brought into mesh with the ring gear l2 to crank the primary engine.

The drive shaft 11 is driven from the starting engine fiy wheel through a conventional clutch comprising a stack of clutch plates I9 having a splined connection with the interior of a recess 20 provided in the fly wheel. The clutch plates are adapted to be compressed between pressure plates 2 I having splined connections with a driven shaft 22 supported for rotation in bearings 23 and 24 carried in the starting engine fly wheel l3 and the housing It respectively. The clutch driven shaft carries a gear 25 which meshes with a gear 26 carried on the end of the drive shaft I1 and secured against axial movement by a nut 21. The drive shaft I1 is supported for rotation in spaced bearings 28 and 29 carried in a housing 3| interposed between the housings l0 and i6 enclosing the fly wheels of the primary engine and starting engine respectively. The housing 3! is adapted to contain lubricating oil for the lubrication of the drive shaft parts and is provided with seals 32 and 33 to prevent the leakage of oil into the adjacent housings.

-Engagement of the clutch to transmit the drive from the fly wheel to the driven shaft is accomplished by compressing the clutch plates through a plurality of cam levers only one of which is illustrated at 35 as supported for rocking movement about a pin 36 carried in a spider 31 having a threaded connection with the periphery of the driven shaft. The ends of the cam levers are received within rearwardly converging recesses 38 provided in a sliding collar,

39 carried for sliding movement on the driven shaft so that sliding movement of the collar effects engagement or release of the clutch. The

periphery of the sliding collar 33 is provided with a groove 40 for the reception of the inwardly extending ends of a yoke 4| secured to a shaft 42 extending through and supported for rotation in the housing l6. At its extending end the shaft 2 carries a lever 43 permitting manual operation of the clutch. The .clutch includes a brake for the driven shaft comprising a brake disc 44 supported for axial sliding movement but held against relative rotation by a guide pin v45 extending from the housing l through a suitable opening in the disc. The brake disc embraces the hub of gear 25 carried .on the clutch driven shaft and is adapted to be pressed into frictional engagement with a flange 46 providedon the gear hub by movement of the sliding collar 39 away from its engaged position as is illustrated in Fig. 1.

The pinion gear i8 is .provided with a splined connection with the drive shaft I1 and is adapted for sliding-movement thereon to effect engage- "mentor disengagement with the ring gear '12.

The pinion gear is normally urged toward its disengaged position illustrated in broken lines in Fig. l by spring 61 carried in a counterbore-48 in the splined end of the drive shaft. The spring 41 bears against the end of the'counterbore and a collar 49 formed on the end of a control rod "50 carried for sliding movement in an axial bore' provided in the drive shaft. The collar 49 of the control rod'isreceived within an enlarged bore 'in the pinion gear and is held against relative axial movement by a shoulder at the end of the bore enlargement and an internal snap ring At its opposite end the control rod carries a cross bar 52 which is "secured to the control rod by means of a nut 53. Elongated openings '54 are provided in the drive shaft to accommodate the ends of the cross bar 52 which is disposed between the nut 53 and a collar 55 carried'for sliding movement on the exterior of the drive 'shaft and adapted to engage the crossbar to operate the control rod. Collar 55 is provided with a pair'of extending pins 53 adapted to be received'in 'the'bifurcated ends of a shifter yoke ".51 non-rotatably secured to a shaft 53. The shaft 58 is supported for rocking movement in housing 3! and at one end extends through to the exterior of the housing. At its extending end the shaft'tid carries a control lever 59 which is clamped against rotation on'the shaft as by a cap screw 60.

During-starting of the primary engine it is desirable that the pinion gear remain in mesh with ring gear i2 until the primary engine is brought up to sufficient speed to assure its continued operation. In order 'to retain the pinion in mesh with the ring gear during this period against the action of spring 41 a pair of pawls 62 are, pivotally supported about pins 63 in a diametrically disposed slot 64 in the drive shaft. The pawls are engageable with a peripheral groove 65 in the control rod when the pinion is moved into its engaged position as shown by the solid lines. In this position the pawls prevent the return of the pinion to its normal position' of disengagement and are continually urged 'towardthe latching position by a spring 65 which bears at one end against a flanged sleeve 61 carried for'sliding movement on shaft l1 engaggear by the action of ,spring 41.

ing outwardly projecting fingers 68 formed on the pawls and at its opposite end against a nut 69. The nut 59 is provided with a threaded engagement with the periphery of the drive shaft 11 and is locked in its position of adjustment by a jam nut 70. Both nuts are disposed adjacent an opening H provided in the-housing v3! to facilitate adjustment. The opening H is normally closed by a removable cover 12 secured to the housing by cap screws 73. The pawls are designed to act as governor weights upon rotation of the shaft ll consequently when the primary engine has been started and attains a predetermined speed 'the pawls will swing outwardly undercentrifugal force against the action of the spring 65. Upon outward swinging of the pawls thecontrol rod will be released and the pinion will be moved out of engagement with the ring The speed at which the pawls will move out of engagement with the control rod may beadjusted by-manipu- 'lation of nuts 69 and '10.

With the improvedconstruction just described the control mechanism for engaging the pinion gear with the primary engine ring gear is carried within a housing containing lubricating oil. Consequently the control mechanism is always adequately lubricated and is'protected from the accumulation of foreign material which'in the past has been :the cause of undue wear "interfering with the reliable operation 'ofthe 'control mechanism. In addition the control mechanism is of unusually simple design and no part extends beyond the face of the primary "engine fly wheel'to interfere with'the mounting of engine driven equipment.

We claim:

1. In astarting mechanism for an enginehaving a ring gear and a starter driven pinion "gear wherein the pinion gear is slidably supported on a hollow shaft for movement to andi'away from the ring gear, control means for'sliding the pinion gear comprising a rod slidable inlthe hollow shaft, and levermeans engagingthe'irod at a point within the shaft and operable from "an external position to slide the rod.

2. In a'starting mechanism for an engine-having a ring gear and a starter drivenpinion gear wherein the pinion gear is slidably-supportedon a hollow shaft for movement to and away from the ring gear, control means for sliding the pinion gear comprising a rod 'slidable in the hollow shaft, said shaft having diametrically opposed elongated openings therein, a cross bar carried by the rod and extending through said REFERENCES CITED The following references are of 'recordin the file of this patent:

UNITED STATES PATENTS Name Date Klein et a1. June-3, 1941 Number 

